Photographic antihalation components



United States Patent 3,364,029 PHOTOGRAPHIC ANTIHALATION COMPONENTS JohnA. Haefner and Thomas I. Abbott, Rochester, N.Y., assignors to EastmanKodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing.Filed July 16, 1964, Ser. No. 383,251 20 Claims. (Cl. 96-84) Thisinvention concerns antihalation layer components which provide lightabsorbent material which can be destroyed or removed by normalphotographic processing.

It is desirable in photographic products to have some form ofantihalation layer which absorbs light to avoid undesirable reflectionsfrom the film base or interfaces between the emulsion layer and the filmbase, causing additional exposure of the silver halide emulsion. In aconventional method, an antihalation layer containing pigments or dyeswhich can be easily removed in an alkaline solution, is coated on thereverse side of the film base. Normal processing in an alkalinedeveloper solution causes the antihalation layer to be dissolved.However, when the alkaline soluble material, used as a carrier for theantihalation dye or pigment, is dissolved, this results in contaminationof the developer solution.

The neutral density, which is desired, has usually required two or threedyes to obtain a neutral absorption of the light across the spectrum.This is particularly important in color processes requiring a neutraldensity layer such as that disclosed in Millikan US. application Ser.No. 159,057, filed Dec. 13, 1961, now abandoned.

In some photographic elements substances have been added directly to thesilver halide emulsion, such as carbon black or other pigments whichserve to absorb light, but these materials are not easily removed andadd to the overall density of the processed photographic element. Thistype of antihalation material is used in photographic products where thesupport is opaque, such as paper, aluminum or similar material.

It has been desirable to find a material with a neutral color whichwould act as an antihalation material which can be added either to theemulsion itself or to an undercoating, but which could be removed ordestroyed during normal photographic processing without contaminatingthe processing solution. However, such a material would have to becompatible with a light sensitive coating such as a silver halideemulsion and should not appreciably alfect the speed of the emulsionwhen incorporated directly therein or utilized contiguous thereto.

We have found that oxodi-(S-quinolyloxo)-van-adic (V) acid (commonlycalled vanadium oxinate) can be used as an antihalation agent.

One object of this invention is to provide an antihalation materialwhich provides a light absorbing substance which can be removed in analkaline solution. Another object is to provide a photographic elementhaving an incorporated antihalation layer in which the light absorbingmaterial can be removed during normal photographic processing. A furtherobject is to provide an antihalation material which is compatible with alight sensitive silver halide emulsion and which does not have anappreciable alfect on the speed of the silver halide emulsion when usedas an undercoat for antihalation purposes. A still further object is toprovide a method of obtaining antihalation protection for a lightsensitive element on the same side of the support as the silver halideemulsion. Additional objects will be apparent from the followingdisclosure.

In carrying out our invention, we employ an 8-hydroxyquinoline vanadiumcomplex. In our preferred embodiment, the vanadium oxinate, dispersed ina Water permeable colloid such as gelatin, or other hydrophilic mate-3,364,029 Patented Jan. 16, 1968 rials, such as collodion, albumin,cellulose derivatives,

certain synthetic resins (polyvinyl alcohol) and the like,

is used as an undercoat. Over this material is coated the lightsensitive silver halide emulsion. When the exposed 5 light sensitiveemulsion is developed in an alkaline solution, the vanadium oxinateloses its color. For some purposes, the vanadium oxinate may also beincorporated directly in the emulsion. It may be used as an overcoat forproviding an overall density or when exposure is to be made through thesupport.

The following generic formula illustrates the vanadium complexes whichcan be used:

R may be the same or different and represents H, SO H, halogen, carboxy,acyl, substituted acyl, alkyl (1-20 carbon atoms), aryl, etc.

R represents the same group as R but also u-anilinobenzyl andsubstituted a-anilinobenzyl.

The following 8-hyd-roxyquinoline derivatives are typical of those, forexample, which form complexes with vanadium (V), which can be used asremovable antihalation layers:

(A) (B) (C) SlOaH 810311 I I I I N/ l N/ OH OH (D) 0 0 OH +=o l l I N NOH OH (H) (I) 31 CHiOH I l I N N OH ()H i NHCH N/ o o 0 OH OH Polymericcomplexe may also be utilized for antihalation protection. For example:

5,5-methylene bis(8-quinolinol) yields the following t complex in whichX represents an integer greater than 1:

u Al -Q CH2 l x Any bifunctional group that doesnt destroy the color ofthe pigment may be substituted for the CH in linking the twohydroxyquinoline rings.

A useful amount of from 5 mg. to 2.5 grams per square foot of thevanadium oxinate may be employed in the gelatin-undercoat. However, moreor less of the material may be utilized depending on the densityrequired and the ability to remove the material during the processingcycle.

The particular supports are not critical and include those known in theart, including paper, glass, metal, polymeric materials such ascellulose acetate, polyesters, polystyrene, polyolefins, polyamides,etc. The light sensitive silver halide may be conventional silver saltssuch as silver chloride, silver bromide, silver iodide, silverchlorobromide, silver chloroiodide, silver bromoiodide and silverbromochloroiodide.

It will also be understood that this antihalation material can be usedin an undercoat or in any layer of a multilayer system. It may be usedwith advantage in a diflfusiou transfer system where the light sensitiveemulsion is coated on a paper support or in a system wherein a silverhalide emulsion is coated over a nucleated layer and the light sensitiveemulsion removed following exposure, development and formation of apositive image in the nucleated layer. It may also be used in colloidtransfer systems and in the formation of lithographic plates where theemulsion is coated on a support which does not permit the use of anantihalation layer which must be removed in its entirety.

It will be appreciated that the particle size of the pigment is notcritical but depends upon the desired dispersion, the method ofdispersing the pigment, such as, for instance, whether it is in acontiguous layer, in the light sensitive composition, etc., or the like.A useful average particle size is from 12 microns and the pigment may beobtained by any of the conventional methods of preparing pigments suchas by precipitation, ball-milling, etc.

It will also be appreciated that the light sensitive emulsions which canbe used with the antihalation material of this invention may besensitized chemically, spectrally, etc., employing compounds known inthe art for these purposes.

The antihalation layers of this invention can be used where such layersare useful, under any light sensitive materials. For instance, they canbe used under light sensitive materials such as those shown in U.S.Patent 2,548,- 537, Example 2, and U.S. Patent 2,791,504, column 5,lines 39-62.

The antihalation compounds of this invention can be used, for example,under light sensitive azide polymer layers such as those described inU.S. Patent 2,948,610; light sensitive cinnamic acid ester polymersdescribed in U.S. Patent 2,690,966; bichromate sensitized materials suchas those described in U.S. Patent 2,448,861; the light sensitive layersdescribed in U.S. Patent 3,038,800 and in the product described in U.S.'Patent 2,607,683.

The following examples are intended to illustrate our invention but notto limit it in any way.

Example 1 To a stirred solution of 75 ml. of 10% gelatin solution at 40C. was added a solution of 3 grams of 8-hydroxyquinoline in ml. ofethanol followed by a warm solution of 1.3 grams of sodium metavanadatein 25 ml. of water. The pH of the solution then was lowered to between 5and 6 by addition of aqueous citric acid. As this was done, the blackvanadium complex formed as a dispersion in the gelatin solution. Thedispersion was coated at various thicknesses on a thin base. A sample ofdispersion diluted 1:1 with 5% gelatin solution was coated on celluloseacetate film base at approximately 10 mL/ft. to give a layer with adiffuse transmission density of 0.72. A sample of this coating wasimmersed in Kodak Developer D-72 at room temperature for two minutes,washed with a little water, immersed in acid sodium thiosulfate fix andthen given a final wash. This treatment reduced the transmission densityto 0.06.

Example 2 A warm dispersion prepared as in Example 1 was chill set,noodled, and washed one hour after it had been kept one hour at roomtemperature. This dispersion was diluted with one part of 5% gelatinsolution and coated as in the first example. A sample coated atapproximately 10 mL/ft. had a diffuse transmission density of 0.79.Immersion of this coating in Kodak Developer D-72 and fix as describedabove reduced the transmission density to 0.12.

Example 3 (A) A solution of 14.2 grams of 8-hydroxyquinoline in 200 m1.of alcohol and a solution of 6.0 grams of sodium meta-vanadate in ml. ofwater were added to 300 grams of 10% gelatin at 40 C. The pH was loweredto 5.0 by slow dropwise addition of 2N sulfuric acid. The resultingdispersion of black complex was stirred 5 minutes at 40 C. beforechilling. After the gelatin was set the dispersion was noodled andwashed for five hours. The washed noodles were melted, 50 grams of 10%gelatin was added and the dispersion was diluted to 1500 ml. with water.This composition was coated on a clear film base at 6.4 g./ft. to give adensity of 0.34. The film was overcoated with a fine-grain silverchlorobromide gelatin emulsion at mg. Ag/ft. and 222.5 mg. gelatin/ft?(B) 6.75 grams of 8-hydroxyquinoline-5-sulfonic acid was suspended in100 ml. of water. Sodium hydroxide solution was added to bring the pH to7.2 and a solution of ferric ammonium citrate (3.1 grams in 4.5 ml. ofwater) was added. After stirring for one hour at 20 C., the pH wassteady at 6.0. The deep colored solution was filtered and evaporated todryness under a vacuum to yield 9.0 grams of ferric complex of8-hydroxyquinoline-5-sulfonic acid. To 34 ml. of an aqueous solutioncontaining 2 grams of the ferric complex ofS-hydroxyquinoline-S-sulfonic acid was added 200 grams of gelatin. Theresulting solution was diluted to 500 ml. and coated on a film base at11.3 grams per square foot to give a layer of a density of 0.20. A finegrain silver chlorobromide emulsion was coated over the layer as in partA.

The same chlorobromide emulsion was coated on a transparent film basewith a conventional antihalation backing on the reverse side as acontrol. The antihala tion layer contained a dispersion of carbon blackin a binder which remains stabilized in an alkaline developer solutionand was removed in solution. After exposure of samples of each coatingon an Eastman Ib Sensitometer, the strips Were developed in thefollowing developer for 2 minutes at 80 F.

. Grams Elon (N-methyl-p-aminophenol sulfate) 2.2 Na2S'O3 (anhydrous)72.0 Hydroquinone 8.8 Na CO (anhydrous) 130.0 KBr 4.0

H 0 to make 1 liter.

The following results were obtained:

Relative Speed Contrast Control. 100 2. 2 A 82 1. 9 B 12. 3 1. 86

The pigment of the invention can also be coated in a layer whichcontains a synthetic vehicle along with gelatin. The pigment isdecolorized and washed out of a synthetic vehicle-gelatin layer just asit is in an all gelatin layer.

The ferric compound is soluble and, therefore, is not readily dispersedin a light sensitive coating. Moreover, the iron compound does not havea neutral color but was greenish, which is generally unsatisfactory forphotographic purposes. When used with a light sensitive silver halideemulsion, the iron compound desensitizes the emulsion as is evident fromthe above table.

Example 4 A coating on a clear base of vanadium oxinate in a layercontaining two parts of the polymer latex of copoly-(butylacrylate-acrylic acid) (90:10 weight ratio) to one part of gelatin wasprepared so that a density of 0.68 resulted. A sample of this coatingwas processed for two minutes at 80 C. in a Metol-hydroquinone developerfollowed by two minutes in acid sodium thiosulfate fix and then wasWashed for 30 minutes. The density of the sample was'reduced to 0.05 bythis treatment.

Example 3 describes vanadium oxinate as a pigment used in a gelatinlayer beneath a silver halide emulsion layer. This pigment can also beused in a non-gelatin antihalation backing layer in which the pigmentand the binder are removed during normal photographic processing. Such abacking has the advantage over those containing carbon or similarpigments which do not dissolve, in that no dark color or sludge isintroduced into the processing solutions.

Example 5 To 50 ml. of water were added 1.0 gram of vanadium oxinate and2.0 m1. of 28% ammonium hydroxide. The mixture was stirred two hours toobtain a solution. To this solution was added 1.5 grams ofcopoly(methacrylic acid-methyl methacrylate) (1:1 mole ratio); stirringwas continued until the polymer dissolved. The solution was coated on apolyterephthalate film base at approximately 5 ml./ft. and then dried togive a film with a density of 0.65. On standing, the density rose to0.86.

A sample of this coating was agitated for one minute in aMetol-hydroquinone developer and then given a brief wash. The density ofthe processed film was 0.04; that is, the same as that of the base. Theused developer solution contained no dark colored or insoluble material.

The same behavior was observed with a coating of vanadium oxinate in awater-organic solvent mixture containing cellulose acetate hydrogenphthalate as the polymeric binder.

Example 6 A dispersion of vanadium oxinate in 4.5% gelatin prepared asin Example 3 was melted to 40 C. and varying amounts were added to afine-grain silver chlorobromide emulsion at 40 C. to give a range ofpigment to silver ratios from 2 grams of pigment per mole of silver to25 gram-s of pigment per mole of silver. The various mixtures werecoated on a polyterephthalate film base to give a constant silvercoverage of 236 mg./ft.

The coatings were processed four minutes in D-19 developer followed by asodium thiosulfate fix and a wash. This treatment gave, with eachcoating, a clear film with no residual pigment density or stain.

It will be appreciated that the 8-hydroxyquinoline vanadium complexes ofthis invention can be used over coatings which are sensitive to highenergy rays such as silver halide emulsions intended for use withX-rays, beta rays, gamma rays, cosmic rays, and the like. The sensitivecoatings can be provided with an overcoating containing theS-hydroxyquinoline vanadium complex of sufficient density to avoidexposure of the sensitive coating from light rays, yet the sensitivecoating can be exposed through the protective coating to high energyrays. Upon development with a customary alkaline developing bath, orupon imbibing alkaline solution, the complex becomes colorless and theimage is readily visible. Various modifications of coatings and layersmay be used depending upon the intended purpose. For instance, there maybe a sensitive coating on each side of the support with a complexcontaining layer over each of the sensitive coatings. For some purposes,there may be an incorporated intensifying screen which can be used inconjunction with the sensitive coating.

As used herein, coatings sensitive to high energy rays are intended toinclude those which may be light sensitive but which are primarilyintended for use with radiations other than visible light, includingX-rays, gamma rays, cosmic rays and the like.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

We claim:

1. A photographic element comprising a support having thereon at leastone light sensitive coating and having on the same support at least onelayer containing an 8-hydroxyquinoline vanadium complex which becomessubstantially colorless under alkaline conditions.

2. A photographic element comprising a support having thereon at leastone light sensitive silver halide emulsion and having on the samesupport at least one layer containing an S-hydroxyquinoline vanadiumcomplex which becomes substantially colorless under alkaline conditions.

3. A photographic element comprising a support having thereon a lightsensitive silver halide emulsion containing an 8-hydroxyquinolinevanadium complex which becomes substantially colorless under alkalineconditions.

4. A photographic element comprising a support having on at least oneside a silver halide emulsion and on the same support at least one layercontaining an 8-hydroxyquinoline vanadium complex which becomessubstantially colorless under alkaline conditions.

5. A photographic element comprising a support having on at least oneside a silver halide emulsion sensitive to high energy rays and havingon the same support at least one layer containing an 8-hydroxyquinolinevanadium complex which becomes substantially colorless under alkalineconditions.

6. A photographic element comprising a support having on at least oneside a silver halide emulsion sensitive to high energy rays andcontaining an 8-hydroxyquinoline vanadium complex which becomessubstantially colorless under alkaline conditions.

7. A photographic element comprising -a support having thereon a lightsensitive coating and contiguous thereto at least one layer containingan 8-hydroxyquinoline vanadium complex having the following formula:

in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (120 carbon atoms), substitutedacyl (1-20 carbon atoms), alkyl (120 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,a-anilinobenzyl and substituted a-anilino-benzyl.

9. A photographic element comprising a support having on at least oneside a silver halide emulsion sensitive to high energy rays and havingcontiguous thereto at least one layer containing an S-hydroxyquinolinevanadium complex having the following formula:

RR F.

in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (1-20 carbon atoms) substitutedacyl (1-20 carbon atoms) alkyl (l20 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,a-anilinobenzyl and substituted tx-anilinobenzyl.

10. A photographic element comprising -a support having thereon a lightsensitive silver halide emulsion containing an 8-hydroxyquinolinevanadium complex having the following formula:

in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (120 carbon atoms), substitutedacyl (l20 carbon atoms), alkyl (120 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,a-anilinobenzyl and substituted ot-anilinobenzyl.

11. A photographic element comprising a support having thereon at leastone light sensitive coating and having contiguous thereto at least onelayer constaining an 'antihalation protecting amount of anS-hydroxyquinoline vanadium complex which becomes substantiallycolorless under alkaline conditions.

12. A photographic element comprising a support having thereon a lightsensitive silver halide emulsion and having contiguous thereto at leastone layer containing an antihalation protecting amount of an8-hydroxyquinoline vanadium complex which becomes substantiallycolorless under alkaline conditions.

13. A photographic element comprising a support having on at least oneside a silver halide coating sensitive to high energy rays and havingcontiguous thereto at least one layer containing an 8-hydroxyquinolinevanadium complex sufficient to render the layer substantially opaque tovisible light, said complex rendered substantially colorless underalkaline conditions.

14. A photographic element comprising a support having thereon a lightsensitive coating and having contiguous thereto at least one layercontaining an antihalation protecting amount of an 8-hydroxyquinolinevanadium complex having the following formula:

in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (1-20 carbon atoms), substitutedacyl (l-20 carbon atoms), alkyl (1-20 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,u-anilinobenzyl and substituted a-anilinobenzyl.

15. A photographic element comprising a support having thereon a lightsensitive silver halide emulsion and having contiguous thereto at leastone layer containing an antihalation protecting amount of an8-hydroxyquinoline vanadium complex having the following formula:

in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (1-20 carbon atoms), substitutedacyl (1-20 carbon atoms), alkyl (1-20 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,a-anilinobenzyl and substituted a-anilinobenzyl.

16. A photographic element comprising a support having on at least oneside of the support a coating sensitive to high energy rays andcontiguous to the sensitive coating, at least one layer containing an8-hydroxyquinoline vanadium complex in an amount sufiicient to renderthe layer substantially opaque to visible light, said complex having thefollowing formula:

R R in which R represents a group selected from the class consisting ofhydrogen, SO H, halogen, carboxyl, acyl (1-20 carbon atoms), substitutedacyl (1-20 carbon atoms), alkyl (1-20 carbon atoms) and aryl, and Rrepresents a member selected from the class consisting of R,ot-anilinobenzyl and substituted ot-anilinobenzyl.

17. A photographic element comprising a support having thereon a lightsensitive silver halide emulsion containing an antihalation protectingamount of an S-hydroxyquinoline vanadium complex having the followingformula:

in which R represents a group selected from the class consisting ofhydrogen, SO H, halo-gen, carboxyl, acyl (1-20 carbon atoms),substituted acyl t1-20 carbon atoms, alkyl (1-20 carbon atoms) and aryl,and R represents a member selected from the class consisting of R,a-anilinobenzyl and substituted oz-anilinobenzyl.

18. A photographic element comprising a support having thereon a lightsensitive coating and having contiguous thereto at least one layercontaining vanadium oxinate.

19. A photographic element comprising a support having thereon a lightsensitive silver halide emulsion and having contiguous thereto at leastone layer containing vanadium oxinate.

20. A photographic element comprising a support having thereon a silverhalide emulsion containing vanadium oxinate.

References Cited Chemistry of Some 8-Hydroxyquin- Vanadium, Chem.Abstracts, 1958

1. A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING THEREON AT LEASTONE LIGHT SENSITIVE COATING AND HAVING ON THE SAME SUPPORT AT LEAST ONELAYER CONTAINING AN 8-HYDROXYQUINOLINE VANADIUM COMPLEX WHICH BECOMESSUBSTANTIALLY COLORLESS UNDER ALKALINE CONDITIONS.